Among working machines such as an excavator having a working device with, for example, a boom, a stick, and an arm, and provided at an upper turning body axially supported to be rotatable on a lower traveling body, some working machines have a function of preventing the working device from interfering with (contacting) certain portions when the upper turning body is turned or components of the working device are operated in accordance with an operation of an operator.
For example, there is known a configuration in which a height of a working device is detected and an operation of turning an upper turning body is stopped when the height of the working device becomes a predetermined value or less during the turning operation (for example, see Patent Literature 1).
Further, as a technology of preventing interference when a load is loaded onto a load receiving member such as a truck, there is known a configuration in which an upper turning body is provided with a distance measurement instrument and an operation of turning the upper turning body is stopped when the upper turning body is too close to the load receiving member based on a distance measured by the distance measurement instrument during the turning operation (for example, see Patent Literature 2).
Furthermore, there is known a configuration in which a danger region is set in upper, lower, and front areas of a working machine in order to prevent a working device from contacting a barrier, and the working device is stopped while decelerating before the working device contacts the barrier (for example, see Patent Literature 3).